Udo Edet E, Boswihi Samar S, Mathew Bindu, Noronha Bobby, Verghese Tina, Al-Jemaz Aisha, Al Saqer Fatma
Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait.
Infect Drug Resist. 2020 Feb 21;13:617-626. doi: 10.2147/IDR.S237319. eCollection 2020.
Methicillin-resistant . (MRSA) belonging to clonal complex 15 (CC15-MRSA) is rare among clinical isolates with few reports from retail camel meat and human patients. This study investigated the genetic relatedness of CC15-MRSA isolated for the first time from patients in Kuwait hospitals.
Antibiotic susceptibility was tested by the disk diffusion method. Minimum inhibitory concentration was determined using Etest strips. Molecular typing was performed using tying, multilocus sequence tying and DNA microarray.
Of 1327 MRSA isolates, 42 (3.1%) were identified as CC15-MRSA. The 42 isolates belonged to sequence type ST1535-harbored SCC type V and types t084 (36 isolates), t346 (3 isolates) and one of t114, t228 and t7583. All 42 isolates were resistant to gentamicin, kanamycin, fusidic acid and cadmium acetate; 38 isolates were resistant to tetracycline. The isolates harbored and that codes for gentamicin and fusidic acid resistance, respectively. was present in the tetracycline-resistant isolates. In addition, the 42 isolates carried (lincosamide nucleotidyltransferase) that confers resistance to lincomycin and clindamycin although phenotypically susceptible to these antibiotics. The isolates belonged to accessory gene regulator type II and capsular polysaccharide group 8 but lacked genes for , toxic shock syndrome toxin, collagen-binding adhesins and Panton-Valentine leukocidin.
This study revealed the emergence and transmission of a previously rare MRSA clone among human patients in Kuwait hospitals and highlights the increasing infiltration of rare MRSA into the human population.
属于克隆复合体15（CC15-MRSA）的耐甲氧西林金黄色葡萄球菌在临床分离株中较为罕见，零售骆驼肉和人类患者的相关报道较少。本研究调查了首次从科威特医院患者中分离出的CC15-MRSA的遗传相关性。
采用纸片扩散法检测抗生素敏感性。使用Etest试纸条测定最低抑菌浓度。采用多位点序列分型、全基因组测序和DNA微阵列进行分子分型。
在1327株耐甲氧西林金黄色葡萄球菌分离株中，42株（3.1%）被鉴定为CC15-MRSA。这42株分离株属于序列型ST1535，携带V型葡萄球菌盒式染色体（SCC），分型为t084（36株）、t346（3株）以及t114、t228和t7583中的一种。所有42株分离株均对庆大霉素、卡那霉素、夫西地酸和醋酸镉耐药；38株对四环素耐药。这些分离株分别携带编码庆大霉素和夫西地酸耐药性的aacA-aphD和fusB。tet(M)存在于耐四环素的分离株中。此外，这42株分离株携带赋予对林可霉素和克林霉素耐药性的lnu(A)（林可酰胺核苷酸转移酶），尽管其表型对这些抗生素敏感。这些分离株属于辅助基因调节因子II型和8型荚膜多糖组，但缺乏肠毒素、毒性休克综合征毒素、胶原结合黏附素和杀白细胞素的基因。
本研究揭示了科威特医院人类患者中一种先前罕见的耐甲氧西林金黄色葡萄球菌克隆的出现和传播，并强调了罕见耐甲氧西林金黄色葡萄球菌在人群中的日益渗透。
